Drive chain



H. s. P lERCE.

DR| VE CHAIN APPLICATION FILED NOV. 1, 1919.

13313035 Patented Oct. 3, 1922.

2 SHEETS-SHEET I.

H. S. PIERCE.

DRIVE CHAIN.

APPLICATION FILED NOV. 7.1919.

1,431,035, Patented bet. 3, 1922.

2 SHEETS -SHEET 2.

I HHH Fatented Flirt. 3, I922.

2 Lisa as? naaotn s. rrnaon, or more. NABOLIS, INDIANA. essrenoa T trimester or CHICAGO, ILLINOIS, a coaroaarroi-r or rumors.

concern.

DRIVE CHAIN.

Application filed November 7, 1319. Serial No. 336,524.

To all whom it may concern Be it known that I, l-IAnoLn Fl. PIERCE, a citizen of the Ilnit 31 States, and a resident of Indianapolis, county of Marion. State of Indiana, have invented certain Improvements in Drive Chains, of which the following is a specification.

My invention relates to certain improve ments in drive chains in which the links are of a given pitch and in which the ends of the chain must. be connected so that the chain can'be used as a drive chain in passing around sprocket wheels. In some instances, the chains are of the proper pitch length. so that they can be coupled without the use of oifset links, but, in some cases, owing to the distance between the centers of the shafts on which the sprocket wheels are mounted, it is necessary to provide chains of a length equivalent to an odd number of: total pitches. Offset links are used to connect the ends of the chain. The objection to offset links is that they are not so'strong as the straight links and are liable to be elongated, owing to the offset.

One object of the invention is to strengthen the chains in which the otlset links are necessary.

A further object of the invention is to design the chain so that straight links can be combined with the olfset links the joint.

In the accompanying drawings:

Fig. 1 is a plan view of sufficient length of a drive chain to illustrate my invention;

Fig. 2 is a side view of the chain illustrated in Fig. 1;

Figs. 3 and 4 are views illustrating modifications of the invention; and

Fig. 5 is a view, in diagram, of a chain with two sections of straight and offset links.

In the drawings, I have illustrated a type of chain in which the links are provided with teeth, which mesh with the teeth of a sprocket wheel. It will be understood that the type of chain may be modified without departing from the essential features of the invention.

1 is a series of straight links coupled together by pivot pins 2 which extend entirely through the links and through washers 3 and 4 at each end. The pivot pins on the ordinary type of chains are riveted over the washers so that the body of the chain is a permanent structure.

In Fig. 1, I have illustrated the links 1 arranged in pairs, one pair of one series alternating with those otthe other series, the outside links of alternate pairs being single links. In the present instance, the links 5 are extended so as to form guide links to hold the chain laterally onthe sprocket wheels. The means for holding the links in position may be modified without departing trointhe spirit of the invention.

6 are the ofiset links. These olfset links are usually arranged in a series across the chain and constitute the sole connection between, the two ends of the chain and if e2:- cessive strains be place-d upon the chains the offset links will straighten out and destroy the pitch. By my invention, I use both ofiset links 6 and plain links 1 at the joint, as in Fig. 1, thus materially strengthening the joint, as the straight links 1 resist the tension and prevent the strai htening of the onset portions of the 0 set links.

By arranging one set of ofi'set links on two pins, as shown at 0., and the remainder, as at b, the same number of ofi'set links is used as heretofore, with an equal number of straight links. It will be seen that a coupling can be made where oft'set links are necessary in such a manner that the ofiset links can be combined with strai ht links so as to materially strengthen the oint and overcome the objection to the oilset link construction.

In Fig. 1, I have illustrated a chain of a given length having three sets of oliset links on one section a and two sets of offset links on a section b.

In Fig. 3, I have illustrated a chain in which the arrangement of the olfset links is extended in the same width of the chain as in Fig. 1, so that in one series there are four offset links and six straight links and in the next series four oflset links and six straight links, while in the next series there are two ofl'set links and eight straight links.

In Fig. 4, I have illustrated a narrow chain, in which the links are extended so as to form three series of two ofiset and four straight links.

In making up a drive chain of the above type, two or more sections, having the com.- bined straight and oilset links, are located in the chain, as shown in the diagram view,

offset links and a single pivot pin of one of the sections.

It will be seen from the above construction that I strengthen a drive chain of this type and prevent the ofiset links from lengthening in service and also prevent the chain from losing pitch.

I claim:

1. The combination in a drive chain, of a series of straight links; pivot pins connecting the links; and a combination of alternating sets of ofiset and straight links in the same pitch connecting the ends of the chain.

2. The combination in a drive chain, of a series of straight links; pivoted pins connecting the links; and a combination of one or more ofli'set links alternating with one or more straight links in the same pitch, conneoting the ends of the chain.

3. The combination in a drive chain, of a series of straight links; pivot pins connecting the links; and two series of ofiset links alternating with straight links connecting the two ends of the chain, the straight links preventing the straightening of the offset links and also preventing the chain from losing pitch.

4.. The combination in a drive chain, of a series of chain links; and a connection when oclgl number of pitches is necessary, said connection consisting of a series of offset links and a like number of straight links with which the ofi'set links alternate.

3. The combination in a drive chain of the silent type, consisting of a series of links having teeth arranged to engage the teeth or" a sprocket wheel; and two series of toothed offset links and two series of toothed straight links with which the offset links HAROLD S. PIERCE. 

